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I am looking at a 73 Mach 1 that has a vin number and door tag that indicate that it has a Q code 351. What are the give aways that it does indeed still have the 351 Cobrajet Q code in it? Any links or info on this model would be greatly appreciated.
 

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Well, for starters in 73 the Q wasn't a cobrajet or even a ram air. The Q just stands for 4 barrel heads and carb. Low compression open heads at that. They are not very rare, if it has the stock autolight 4v carb, it should be a real Q.
 

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4v cast iron SPREAD BORE intake and carb the corners at the front top of the heads have a 4 on them the c-6 if auto, or 4 speed, there should be a 3.25 rear ratio 9 inch ( if it had air) there is only 1 way to tell the block you have to pull the front timing cover and look for 4 bolt mains ( not on the end caps though) hope this helps
 

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sorry john the q code 71-74 1974 IN COUGARS is indeed a cobra jet and not that commen i can put up some numbers when i get my marti book at home.
 

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Ok, they may have called it a cobrajet, but should anything that only made 156 hp really carry that name? I'd put a 71 Q code against a 73 Q code any day of the week. Don't get me wrong, I know it has great potential, but the name is a little misleading. It was the only 4v avilable that year, no more R code.
 

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wow my 71 -73 are really misunderstood
in 1971 the q code ( a rare mustang) i have 1 of 7 4 spd coupes, made 285 hourse power
in 1972 due to lower compression ( done with istons not cylinder heads) it made 266 hourse power
in 1973 it made 266 hourse power
if equiped with a auto it was a c-6 with a factory high stall converter, it had 2 piece wrap around moot mounts( basiclly making them solid)
you are correct that the 71 made more hourse power ( 19 more) and what would that translate to rear wheel?
nice looking vert
hope this helps
AL
 

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Ease up there John!Who told you that the 73 Qcode only put out 185 H.P.? The 73 Qcode is and was a Cobra Jet! The only differance was in the cam timing(retarded 4 degrees) I would have had no problem running mine against any of the other years of 351 Cobra jet.I bought mine new(see some of my earlier post for a discriptoin).Like was said you got everything that all the others had EXCEPT for the Ramair option.Factory H.P. was 266. Good looking vert. FastE
 

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To answer some of your questions,some exteranal clues would be a special air cleaner assmbly,the early 73s usually had a chrome lid,the latter ones had a painted top.There should be an extra vacum operated door on the side that lets extra air flow to the carb.It will have the 4 stamped on the corner of the heads next to the front edge of the valve cover.The Harmonic balancer is very thick compared to others.Also look at the altenator drive pulley.It should measure about 3.75" in diameter.It should have a 4 bolt main block(have to pull the pan) The oil pan has special baffeling.It does have special motor mounts as was said,they are interlocked.If it is an auto it will have a c6 with a 10" convertor(when you drive it and get on the gas the trans will almost sound like it is slipping).You should have a 9" rear with a 3:25 ratio with AC. The four speed cars usualy got a 3:50 rear(no air) with 31 spl.axels.
You should also find staggard rear shocks,rear sway bar,etc....
The early 73s also got the through the valance exhaust with the chrome tips,after December they went back to the turned down exhaust like the Boss 351s(this and the non ramair on the Cobra Jets was due to EPA noise regulations that went into effect in January 73)
Ok let me through this out there to I have seen a long time ago some of the publications rated these at 245HP,but I think most would agree that it was 266 HP.
I would say that the 73s are a very good buy!I think that you will find more 73s with Q codes than 71-72s only because Ford had already decided to get away from the Clevelands and was using up their inventory.These were available in74 for the last time in Torinos and Montigos,and they still ran very strong.Hope this helps some. FastE ::

















;25
 

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Really, my mistake then. Everything I've read (guess that's where I went wrong) stated they were > 200 hp engines restricted by lower compression, cam changes, and the wrong (open/quench) chamber type. On top of that the change in the way then enginges where rated. Now that I look again, it seems a lot of sites group the 2v and 4v engine with the same rating, but if they are seperated out it shows 266. I always though Ford had turned the 351c into a wheeser in 73. My bad.
JH
 

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As far as the carb goes it should be a 4300 Spreadbore Motorcraft not an autolite. The last yr for autolites were 71. 72-73 4300's were Motorcrafts. I believe in the blocks it was a crap shoot to get a 4 bolt block or a 2 bolt in a factory Q code car. 266 Horse is what they rated it and a 71 M code 4V was the equal to a Q code in 72-73 4V just for comparison but not equal to HP.
 

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actually the carb should be a 4300 D. (spread bore)
 

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Well, for starters in 73 the Q wasn't a cobrajet or even a ram air. The Q just stands for 4 barrel heads and carb. Low compression open heads at that. They are not very rare, if it has the stock autolight 4v carb, it should be a real Q.
Mercury , did , however, refer to Q code Cougars as, CJ, and Cobra Jet performance package. 4 barrel Cleveland , was available in Cougar, W/O Cobra jet performance package. Staggered rear shocks, rear stabilizer bar, are good giveaways to Q code, in 72,73. Like stated else where, all were supposed to be 4bolt mains. However some were delivered, with standard 2bolt Mains. Dearborn, on a Monday Morning, in 71,72 was an interesting assembly line, I've been told😁.
 
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